Abstract
The pyrimidine synthesis from ethyl ethoxymethylenecyanoacetate (EMCE) and amidines is significantly influenced by the mole ratios of reacting components. In general the use of excess amidine gives better yields. Condensation of EMCE with excess acetamidine gives 4-hydroxy-2-methyl-5-pyrimidinecarbonitrile acetamidinate as the main product in good yield. Reaction between EMCE and excess 2-ethyl-2-thiopseudourea gives 2-ethylthio-4-hydroxy-5-pyrimidinecarbonitrile 2-ethyl-2-thiopseudoureate rather than 3-{3-{[amino (ethylthio) methylene] amino}-2-cyanoacryloyl}-2-ethyl-2-thiopseudourea originally claimed. The condensation reactions of EMCE with other amidines such as guanidine and benzamidine have been studied.
